Default is likely correct. Guitars like Starfires can be a royal PITA to work on, so unless you have experience or are willing to poke around a bit, you might want to take it to someone. Here's a pic of the wiring harness on a '98 Starfire moved to the outside. There's a lot going on in there and it's all routed and hopefully tied down so it doesn't rattle and can't be seen through the f-holes.
Somewhere the ground is connected via a wire to the bridge. It could be from a pickup or even from the selector switch. Anything that's part of the ground bus can be used but my guess would be the bridge pickup because that's a short and easy run. You can run a new ground from anywhere there's an existing ground to the bridge, but the right way to do it is to clean up the existing problem even if it means removing it. If your existing ground is intermittent it can lead to scratching and other noise if you don't remove it.
Additionally, my guess is that the existing ground wire is *just* long enough to reach where its going so you won't be able to easily work on it.
If all of that is overwhelming, bring it to a tech. Be warned that some will charge an up-charge to work on semi-hollows because they're a PITA. Since there's no access panel on the back it's all gotta be done through the f-holes or the pickup routes and you can't see anything. There are tricks that can make it easier, but even with the tricks it's still a PITA.